X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=parsers.c;h=3b08cf91ff2885399eff80377319e69f8e74f28c;hp=9060ea1efbeb07dba01a9f885bbd6c8fdd9b5820;hb=36f5fa200c2685ff053539184c83f1d909f0da05;hpb=1d48f6123b572090c8b04e67c5e6d2a7bc2d7624 diff --git a/parsers.c b/parsers.c index 9060ea1e..3b08cf91 100644 --- a/parsers.c +++ b/parsers.c @@ -1,4 +1,4 @@ -const char parsers_rcs[] = "$Id: parsers.c,v 1.78 2006/12/26 17:19:20 fabiankeil Exp $"; +const char parsers_rcs[] = "$Id: parsers.c,v 1.121 2008/01/05 21:37:03 fabiankeil Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/parsers.c,v $ @@ -10,15 +10,14 @@ const char parsers_rcs[] = "$Id: parsers.c,v 1.78 2006/12/26 17:19:20 fabiankeil * `client_uagent', `client_x_forwarded', * `client_x_forwarded_adder', `client_xtra_adder', * `content_type', `crumble', `destroy_list', `enlist', - * `flush_socket', ``get_header', `sed', `filter_server_header' - * `filter_client_header', `filter_header', `crunch_server_header', + * `flush_socket', ``get_header', `sed', `filter_header' * `server_content_encoding', `server_content_disposition', * `server_last_modified', `client_accept_language', * `crunch_client_header', `client_if_modified_since', * `client_if_none_match', `get_destination_from_headers', - * `parse_header_time' and `server_set_cookie'. + * `parse_header_time', `decompress_iob' and `server_set_cookie'. * - * Copyright : Written by and Copyright (C) 2001-2006 the SourceForge + * Copyright : Written by and Copyright (C) 2001-2007 the SourceForge * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written @@ -45,6 +44,213 @@ const char parsers_rcs[] = "$Id: parsers.c,v 1.78 2006/12/26 17:19:20 fabiankeil * * Revisions : * $Log: parsers.c,v $ + * Revision 1.121 2008/01/05 21:37:03 fabiankeil + * Let client_range() also handle Request-Range headers + * which apparently are still supported by many servers. + * + * Revision 1.120 2008/01/04 17:43:45 fabiankeil + * Improve the warning messages that get logged if the action files + * "enable" filters but no filters of that type have been loaded. + * + * Revision 1.119 2007/12/28 18:32:51 fabiankeil + * In server_content_type(): + * - Don't require leading white space when detecting image content types. + * - Change '... not replaced ...' message to sound less crazy if the text + * type actually is 'text/plain'. + * - Mark the 'text/plain == binary data' assumption for removal. + * - Remove a bunch of trailing white space. + * + * Revision 1.118 2007/12/28 16:56:35 fabiankeil + * Minor server_content_disposition() changes: + * - Don't regenerate the header name all lower-case. + * - Some white space fixes. + * - Remove useless log message in case of ENOMEM. + * + * Revision 1.117 2007/12/06 18:11:50 fabiankeil + * Garbage-collect the code to add a X-Forwarded-For + * header as it seems to be mostly used by accident. + * + * Revision 1.116 2007/12/01 13:04:22 fabiankeil + * Fix a crash on mingw32 with some Last Modified times in the future. + * + * Revision 1.115 2007/11/02 16:52:50 fabiankeil + * Remove a "can't happen" error block which, over + * time, mutated into a "guaranteed to happen" block. + * + * Revision 1.114 2007/10/19 16:56:26 fabiankeil + * - Downgrade "Buffer limit reached" message to LOG_LEVEL_INFO. + * - Use shiny new content_filters_enabled() in client_range(). + * + * Revision 1.113 2007/10/10 17:29:57 fabiankeil + * I forgot about Poland. + * + * Revision 1.112 2007/10/09 16:38:40 fabiankeil + * Remove Range and If-Range headers if content filtering is enabled. + * + * Revision 1.111 2007/10/04 18:07:00 fabiankeil + * Move ACTION_VANILLA_WAFER handling from jcc's chat() into + * client_cookie_adder() to make sure send-vanilla-wafer can be + * controlled through tags (and thus regression-tested). + * + * Revision 1.110 2007/09/29 10:42:37 fabiankeil + * - Remove "scanning headers for" log message again. + * - Some more whitespace fixes. + * + * Revision 1.109 2007/09/08 14:25:48 fabiankeil + * Refactor client_referrer() and add conditional-forge parameter. + * + * Revision 1.108 2007/08/28 18:21:03 fabiankeil + * A bunch of whitespace fixes, pointy hat to me. + * + * Revision 1.107 2007/08/28 18:16:32 fabiankeil + * Fix possible memory corruption in server_http, make sure it's not + * executed for ordinary server headers and mark some problems for later. + * + * Revision 1.106 2007/08/18 14:30:32 fabiankeil + * Let content-type-overwrite{} honour force-text-mode again. + * + * Revision 1.105 2007/08/11 14:49:49 fabiankeil + * - Add prototpyes for the header parsers and make them static. + * - Comment out client_accept_encoding_adder() which isn't used right now. + * + * Revision 1.104 2007/07/14 07:38:19 fabiankeil + * Move the ACTION_FORCE_TEXT_MODE check out of + * server_content_type(). Signal other functions + * whether or not a content type has been declared. + * Part of the fix for BR#1750917. + * + * Revision 1.103 2007/06/01 16:31:54 fabiankeil + * Change sed() to return a jb_err in preparation for forward-override{}. + * + * Revision 1.102 2007/05/27 12:39:32 fabiankeil + * Adjust "X-Filter: No" to disable dedicated header filters. + * + * Revision 1.101 2007/05/14 10:16:41 fabiankeil + * Streamline client_cookie_adder(). + * + * Revision 1.100 2007/04/30 15:53:11 fabiankeil + * Make sure filters with dynamic jobs actually use them. + * + * Revision 1.99 2007/04/30 15:06:26 fabiankeil + * - Introduce dynamic pcrs jobs that can resolve variables. + * - Remove unnecessary update_action_bits_for_all_tags() call. + * + * Revision 1.98 2007/04/17 18:32:10 fabiankeil + * - Make tagging based on tags set by earlier taggers + * of the same kind possible. + * - Log whether or not new tags cause action bits updates + * (in which case a matching tag-pattern section exists). + * - Log if the user tries to set a tag that is already set. + * + * Revision 1.97 2007/04/15 16:39:21 fabiankeil + * Introduce tags as alternative way to specify which + * actions apply to a request. At the moment tags can be + * created based on client and server headers. + * + * Revision 1.96 2007/04/12 12:53:58 fabiankeil + * Log a warning if the content is compressed, filtering is + * enabled and Privoxy was compiled without zlib support. + * Closes FR#1673938. + * + * Revision 1.95 2007/03/25 14:26:40 fabiankeil + * - Fix warnings when compiled with glibc. + * - Don't use crumble() for cookie crunching. + * - Move cookie time parsing into parse_header_time(). + * - Let parse_header_time() return a jb_err code + * instead of a pointer that can only be used to + * check for NULL anyway. + * + * Revision 1.94 2007/03/21 12:23:53 fabiankeil + * - Add better protection against malicious gzip headers. + * - Stop logging the first hundred bytes of decompressed content. + * It looks like it's working and there is always debug 16. + * - Log the content size after decompression in decompress_iob() + * instead of pcrs_filter_response(). + * + * Revision 1.93 2007/03/20 15:21:44 fabiankeil + * - Use dedicated header filter actions instead of abusing "filter". + * Replace "filter-client-headers" and "filter-client-headers" + * with "server-header-filter" and "client-header-filter". + * - Remove filter_client_header() and filter_client_header(), + * filter_header() now checks the shiny new + * CSP_FLAG_CLIENT_HEADER_PARSING_DONE flag instead. + * + * Revision 1.92 2007/03/05 13:25:32 fabiankeil + * - Cosmetical changes for LOG_LEVEL_RE_FILTER messages. + * - Handle "Cookie:" and "Connection:" headers a bit smarter + * (don't crunch them just to recreate them later on). + * - Add another non-standard time format for the cookie + * expiration date detection. + * - Fix a valgrind warning. + * + * Revision 1.91 2007/02/24 12:27:32 fabiankeil + * Improve cookie expiration date detection. + * + * Revision 1.90 2007/02/08 19:12:35 fabiankeil + * Don't run server_content_length() the first time + * sed() parses server headers; only adjust the + * Content-Length header if the page was modified. + * + * Revision 1.89 2007/02/07 16:52:11 fabiankeil + * Fix log messages regarding the cookie time format + * (cookie and request URL were mixed up). + * + * Revision 1.88 2007/02/07 11:27:12 fabiankeil + * - Let decompress_iob() + * - not corrupt the content if decompression fails + * early. (the first byte(s) were lost). + * - use pointer arithmetics with defined outcome for + * a change. + * - Use a different kludge to remember a failed decompression. + * + * Revision 1.87 2007/01/31 16:21:38 fabiankeil + * Search for Max-Forwards headers case-insensitive, + * don't generate the "501 unsupported" message for invalid + * Max-Forwards values and don't increase negative ones. + * + * Revision 1.86 2007/01/30 13:05:26 fabiankeil + * - Let server_set_cookie() check the expiration date + * of cookies and don't touch the ones that are already + * expired. Fixes problems with low quality web applications + * as described in BR 932612. + * + * - Adjust comment in client_max_forwards to reality; + * remove invalid Max-Forwards headers. + * + * Revision 1.85 2007/01/26 15:33:46 fabiankeil + * Stop filter_header() from unintentionally removing + * empty header lines that were enlisted by the continue + * hack. + * + * Revision 1.84 2007/01/24 12:56:52 fabiankeil + * - Repeat the request URL before logging any headers. + * Makes reading the log easier in case of simultaneous requests. + * - If there are more than one Content-Type headers in one request, + * use the first one and remove the others. + * - Remove "newval" variable in server_content_type(). + * It's only used once. + * + * Revision 1.83 2007/01/12 15:03:02 fabiankeil + * Correct a cast, check inflateEnd() exit code + * to see if we have to, replace sprintf calls + * with snprintf. + * + * Revision 1.82 2007/01/01 19:36:37 fabiankeil + * Integrate a modified version of Wil Mahan's + * zlib patch (PR #895531). + * + * Revision 1.81 2006/12/31 22:21:33 fabiankeil + * Skip empty filter files in filter_header() + * but don't ignore the ones that come afterwards. + * Fixes BR 1619208, this time for real. + * + * Revision 1.80 2006/12/29 19:08:22 fabiankeil + * Reverted parts of my last commit + * to keep error handling working. + * + * Revision 1.79 2006/12/29 18:04:40 fabiankeil + * Fixed gcc43 conversion warnings. + * * Revision 1.78 2006/12/26 17:19:20 fabiankeil * Bringing back the "useless" localtime() call * I removed in revision 1.67. On some platforms @@ -559,8 +765,19 @@ const char parsers_rcs[] = "$Id: parsers.c,v 1.78 2006/12/26 17:19:20 fabiankeil #include #include #include + +#ifdef __GLIBC__ +/* + * Convince GNU's libc to provide a strptime prototype. + */ +#define __USE_XOPEN +#endif /*__GLIBC__ */ #include +#ifdef FEATURE_ZLIB +#include +#endif + #if !defined(_WIN32) && !defined(__OS2__) #include #endif @@ -579,6 +796,8 @@ const char parsers_rcs[] = "$Id: parsers.c,v 1.78 2006/12/26 17:19:20 fabiankeil #include "jbsockets.h" #include "miscutil.h" #include "list.h" +#include "actions.h" +#include "filters.h" #ifndef HAVE_STRPTIME #include "strptime.h" @@ -588,7 +807,7 @@ const char parsers_h_rcs[] = PARSERS_H_VERSION; /* Fix a problem with Solaris. There should be no effect on other * platforms. - * Solaris's isspace() is a macro which uses it's argument directly + * Solaris's isspace() is a macro which uses its argument directly * as an array index. Therefore we need to make sure that high-bit * characters generate +ve values, and ideally we also want to make * the argument match the declared parameter type of "int". @@ -599,6 +818,49 @@ const char parsers_h_rcs[] = PARSERS_H_VERSION; #define ijb_isupper(__X) isupper((int)(unsigned char)(__X)) #define ijb_tolower(__X) tolower((int)(unsigned char)(__X)) +static jb_err scan_headers(struct client_state *csp); +static jb_err header_tagger(struct client_state *csp, char *header); +static jb_err parse_header_time(const char *header_time, time_t *result); + +static jb_err crumble (struct client_state *csp, char **header); +static jb_err connection (struct client_state *csp, char **header); +static jb_err filter_header (struct client_state *csp, char **header); +static jb_err client_referrer (struct client_state *csp, char **header); +static jb_err client_uagent (struct client_state *csp, char **header); +static jb_err client_ua (struct client_state *csp, char **header); +static jb_err client_from (struct client_state *csp, char **header); +static jb_err client_send_cookie (struct client_state *csp, char **header); +static jb_err client_x_forwarded (struct client_state *csp, char **header); +static jb_err client_accept_encoding (struct client_state *csp, char **header); +static jb_err client_te (struct client_state *csp, char **header); +static jb_err client_max_forwards (struct client_state *csp, char **header); +static jb_err client_host (struct client_state *csp, char **header); +static jb_err client_if_modified_since (struct client_state *csp, char **header); +static jb_err client_accept_language (struct client_state *csp, char **header); +static jb_err client_if_none_match (struct client_state *csp, char **header); +static jb_err crunch_client_header (struct client_state *csp, char **header); +static jb_err client_x_filter (struct client_state *csp, char **header); +static jb_err client_range (struct client_state *csp, char **header); +static jb_err server_set_cookie (struct client_state *csp, char **header); +static jb_err server_content_type (struct client_state *csp, char **header); +static jb_err server_content_length (struct client_state *csp, char **header); +static jb_err server_content_md5 (struct client_state *csp, char **header); +static jb_err server_content_encoding (struct client_state *csp, char **header); +static jb_err server_transfer_coding (struct client_state *csp, char **header); +static jb_err server_http (struct client_state *csp, char **header); +static jb_err crunch_server_header (struct client_state *csp, char **header); +static jb_err server_last_modified (struct client_state *csp, char **header); +static jb_err server_content_disposition(struct client_state *csp, char **header); + +static jb_err client_host_adder (struct client_state *csp); +static jb_err client_cookie_adder (struct client_state *csp); +static jb_err client_xtra_adder (struct client_state *csp); +static jb_err connection_close_adder (struct client_state *csp); + +static jb_err create_forged_referrer(char **header, const char *hostport); +static jb_err create_fake_referrer(char **header, const char *fake_referrer); +static jb_err handle_conditional_hide_referrer_parameter(char **header, + const char *host, const int parameter_conditional_block); const struct parsers client_patterns[] = { { "referer:", 8, client_referrer }, @@ -612,23 +874,25 @@ const struct parsers client_patterns[] = { { "Host:", 5, client_host }, { "if-modified-since:", 18, client_if_modified_since }, { "Keep-Alive:", 11, crumble }, - { "connection:", 11, crumble }, + { "connection:", 11, connection }, { "proxy-connection:", 17, crumble }, { "max-forwards:", 13, client_max_forwards }, { "Accept-Language:", 16, client_accept_language }, { "if-none-match:", 14, client_if_none_match }, + { "Range:", 6, client_range }, + { "Request-Range:", 14, client_range }, + { "If-Range:", 9, client_range }, { "X-Filter:", 9, client_x_filter }, { "*", 0, crunch_client_header }, - { "*", 0, filter_client_header }, + { "*", 0, filter_header }, { NULL, 0, NULL } }; const struct parsers server_patterns[] = { - { "HTTP", 4, server_http }, + { "HTTP/", 5, server_http }, { "set-cookie:", 11, server_set_cookie }, - { "connection:", 11, crumble }, + { "connection:", 11, connection }, { "Content-Type:", 13, server_content_type }, - { "Content-Length:", 15, server_content_length }, { "Content-MD5:", 12, server_content_md5 }, { "Content-Encoding:", 17, server_content_encoding }, { "Transfer-Encoding:", 18, server_transfer_coding }, @@ -636,32 +900,43 @@ const struct parsers server_patterns[] = { { "content-disposition:", 20, server_content_disposition }, { "Last-Modified:", 14, server_last_modified }, { "*", 0, crunch_server_header }, - { "*", 0, filter_server_header }, + { "*", 0, filter_header }, { NULL, 0, NULL } }; const struct parsers server_patterns_light[] = { { "Content-Length:", 15, server_content_length }, { "Transfer-Encoding:", 18, server_transfer_coding }, +#ifdef FEATURE_ZLIB + { "Content-Encoding:", 17, server_content_encoding }, +#endif /* def FEATURE_ZLIB */ { NULL, 0, NULL } }; const add_header_func_ptr add_client_headers[] = { client_host_adder, client_cookie_adder, - client_x_forwarded_adder, client_xtra_adder, /* Temporarily disabled: client_accept_encoding_adder, */ connection_close_adder, NULL }; - const add_header_func_ptr add_server_headers[] = { connection_close_adder, NULL }; +/* The vanilla wafer. */ +static const char VANILLA_WAFER[] = + "NOTICE=TO_WHOM_IT_MAY_CONCERN_" + "Do_not_send_me_any_copyrighted_information_other_than_the_" + "document_that_I_am_requesting_or_any_of_its_necessary_components._" + "In_particular_do_not_send_me_any_cookies_that_" + "are_subject_to_a_claim_of_copyright_by_anybody._" + "Take_notice_that_I_refuse_to_be_bound_by_any_license_condition_" + "(copyright_or_otherwise)_applying_to_any_cookie._"; + /********************************************************************* * * Function : flush_socket @@ -716,7 +991,7 @@ int flush_socket(jb_socket fd, struct client_state *csp) * or buffer limit reached. * *********************************************************************/ -jb_err add_to_iob(struct client_state *csp, char *buf, size_t n) +jb_err add_to_iob(struct client_state *csp, char *buf, int n) { struct iob *iob = csp->iob; size_t used, offset, need, want; @@ -726,7 +1001,7 @@ jb_err add_to_iob(struct client_state *csp, char *buf, size_t n) used = (size_t)(iob->eod - iob->buf); offset = (size_t)(iob->cur - iob->buf); - need = used + n + 1; + need = used + (size_t)n + 1; /* * If the buffer can't hold the new data, extend it first. @@ -734,7 +1009,7 @@ jb_err add_to_iob(struct client_state *csp, char *buf, size_t n) */ if (need > csp->config->buffer_limit) { - log_error(LOG_LEVEL_ERROR, "Buffer limit reached while extending the buffer (iob)"); + log_error(LOG_LEVEL_INFO, "Buffer limit reached while extending the buffer (iob)"); return JB_ERR_MEMORY; } @@ -776,6 +1051,380 @@ jb_err add_to_iob(struct client_state *csp, char *buf, size_t n) } +#ifdef FEATURE_ZLIB +/********************************************************************* + * + * Function : decompress_iob + * + * Description : Decompress buffered page, expanding the + * buffer as necessary. csp->iob->cur + * should point to the the beginning of the + * compressed data block. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : JB_ERR_OK on success, + * JB_ERR_MEMORY if out-of-memory limit reached, and + * JB_ERR_COMPRESS if error decompressing buffer. + * + *********************************************************************/ +jb_err decompress_iob(struct client_state *csp) +{ + char *buf; /* new, uncompressed buffer */ + char *cur; /* Current iob position (to keep the original + * iob->cur unmodified if we return early) */ + size_t bufsize; /* allocated size of the new buffer */ + size_t old_size; /* Content size before decompression */ + size_t skip_size; /* Number of bytes at the beginning of the iob + that we should NOT decompress. */ + int status; /* return status of the inflate() call */ + z_stream zstr; /* used by calls to zlib */ + + assert(csp->iob->cur - csp->iob->buf > 0); + assert(csp->iob->eod - csp->iob->cur > 0); + + bufsize = csp->iob->size; + skip_size = (size_t)(csp->iob->cur - csp->iob->buf); + old_size = (size_t)(csp->iob->eod - csp->iob->cur); + + cur = csp->iob->cur; + + if (bufsize < 10) + { + /* + * This is to protect the parsing of gzipped data, + * but it should(?) be valid for deflated data also. + */ + log_error(LOG_LEVEL_ERROR, "Buffer too small decompressing iob"); + return JB_ERR_COMPRESS; + } + + if (csp->content_type & CT_GZIP) + { + /* + * Our task is slightly complicated by the facts that data + * compressed by gzip does not include a zlib header, and + * that there is no easily accessible interface in zlib to + * handle a gzip header. We strip off the gzip header by + * hand, and later inform zlib not to expect a header. + */ + + /* + * Strip off the gzip header. Please see RFC 1952 for more + * explanation of the appropriate fields. + */ + if ((*cur++ != (char)0x1f) + || (*cur++ != (char)0x8b) + || (*cur++ != Z_DEFLATED)) + { + log_error(LOG_LEVEL_ERROR, "Invalid gzip header when decompressing"); + return JB_ERR_COMPRESS; + } + else + { + int flags = *cur++; + /* + * XXX: These magic numbers should be replaced + * with macros to give a better idea what they do. + */ + if (flags & 0xe0) + { + /* The gzip header has reserved bits set; bail out. */ + log_error(LOG_LEVEL_ERROR, "Invalid gzip header flags when decompressing"); + return JB_ERR_COMPRESS; + } + cur += 6; + + /* Skip extra fields if necessary. */ + if (flags & 0x04) + { + /* + * Skip a given number of bytes, specified + * as a 16-bit little-endian value. + */ + /* + * XXX: This code used to be: + * + * csp->iob->cur += *csp->iob->cur++ + (*csp->iob->cur++ << 8); + * + * which I had to change into: + * + * cur += *cur++ + (*cur++ << 8); + * + * at which point gcc43 finally noticed that the value + * of cur is undefined (it depends on which of the + * summands is evaluated first). + * + * I haven't come across a site where this + * code is actually executed yet, but I hope + * it works anyway. + */ + int skip_bytes; + skip_bytes = *cur++; + skip_bytes = *cur++ << 8; + + assert(skip_bytes == *csp->iob->cur - 2 + ((*csp->iob->cur - 1) << 8)); + + /* + * The number of bytes to skip should be positive + * and we'd like to stay in the buffer. + */ + if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur))) + { + log_error(LOG_LEVEL_ERROR, + "Unreasonable amount of bytes to skip (%d). Stopping decompression", + skip_bytes); + return JB_ERR_COMPRESS; + } + log_error(LOG_LEVEL_INFO, + "Skipping %d bytes for gzip compression. Does this sound right?", + skip_bytes); + cur += skip_bytes; + } + + /* Skip the filename if necessary. */ + if (flags & 0x08) + { + /* A null-terminated string is supposed to follow. */ + while (*cur++ && (cur < csp->iob->eod)); + + } + + /* Skip the comment if necessary. */ + if (flags & 0x10) + { + /* A null-terminated string is supposed to follow. */ + while (*cur++ && (cur < csp->iob->eod)); + } + + /* Skip the CRC if necessary. */ + if (flags & 0x02) + { + cur += 2; + } + + if (cur >= csp->iob->eod) + { + /* + * If the current position pointer reached or passed + * the buffer end, we were obviously tricked to skip + * too much. + */ + log_error(LOG_LEVEL_ERROR, + "Malformed gzip header detected. Aborting decompression."); + return JB_ERR_COMPRESS; + } + } + } + else if (csp->content_type & CT_DEFLATE) + { + /* + * XXX: The debug level should be lowered + * before the next stable release. + */ + log_error(LOG_LEVEL_INFO, "Decompressing deflated iob: %d", *cur); + /* + * In theory (that is, according to RFC 1950), deflate-compressed + * data should begin with a two-byte zlib header and have an + * adler32 checksum at the end. It seems that in practice only + * the raw compressed data is sent. Note that this means that + * we are not RFC 1950-compliant here, but the advantage is that + * this actually works. :) + * + * We add a dummy null byte to tell zlib where the data ends, + * and later inform it not to expect a header. + * + * Fortunately, add_to_iob() has thoughtfully null-terminated + * the buffer; we can just increment the end pointer to include + * the dummy byte. + */ + csp->iob->eod++; + } + else + { + log_error(LOG_LEVEL_ERROR, + "Unable to determine compression format for decompression"); + return JB_ERR_COMPRESS; + } + + /* Set up the fields required by zlib. */ + zstr.next_in = (Bytef *)cur; + zstr.avail_in = (unsigned int)(csp->iob->eod - cur); + zstr.zalloc = Z_NULL; + zstr.zfree = Z_NULL; + zstr.opaque = Z_NULL; + + /* + * Passing -MAX_WBITS to inflateInit2 tells the library + * that there is no zlib header. + */ + if (inflateInit2 (&zstr, -MAX_WBITS) != Z_OK) + { + log_error(LOG_LEVEL_ERROR, "Error initializing decompression"); + return JB_ERR_COMPRESS; + } + + /* + * Next, we allocate new storage for the inflated data. + * We don't modify the existing iob yet, so in case there + * is error in decompression we can recover gracefully. + */ + buf = zalloc(bufsize); + if (NULL == buf) + { + log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob"); + return JB_ERR_MEMORY; + } + + assert(bufsize >= skip_size); + memcpy(buf, csp->iob->buf, skip_size); + zstr.avail_out = bufsize - skip_size; + zstr.next_out = (Bytef *)buf + skip_size; + + /* Try to decompress the whole stream in one shot. */ + while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH))) + { + /* We need to allocate more memory for the output buffer. */ + + char *tmpbuf; /* used for realloc'ing the buffer */ + size_t oldbufsize = bufsize; /* keep track of the old bufsize */ + + /* + * If zlib wants more data then there's a problem, because + * the complete compressed file should have been buffered. + */ + if (0 == zstr.avail_in) + { + log_error(LOG_LEVEL_ERROR, "Unexpected end of compressed iob"); + return JB_ERR_COMPRESS; + } + + /* + * If we tried the limit and still didn't have enough + * memory, just give up. + */ + if (bufsize == csp->config->buffer_limit) + { + log_error(LOG_LEVEL_ERROR, "Buffer limit reached while decompressing iob"); + return JB_ERR_MEMORY; + } + + /* Try doubling the buffer size each time. */ + bufsize *= 2; + + /* Don't exceed the buffer limit. */ + if (bufsize > csp->config->buffer_limit) + { + bufsize = csp->config->buffer_limit; + } + + /* Try to allocate the new buffer. */ + tmpbuf = realloc(buf, bufsize); + if (NULL == tmpbuf) + { + log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob"); + freez(buf); + return JB_ERR_MEMORY; + } + else + { + char *oldnext_out = (char *)zstr.next_out; + + /* + * Update the fields for inflate() to use the new + * buffer, which may be in a location different from + * the old one. + */ + zstr.avail_out += bufsize - oldbufsize; + zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out; + + /* + * Compare with an uglier method of calculating these values + * that doesn't require the extra oldbufsize variable. + */ + assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out); + assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf)); + assert(zstr.avail_out > 0); + + buf = tmpbuf; + } + } + + if (Z_STREAM_ERROR == inflateEnd(&zstr)) + { + log_error(LOG_LEVEL_ERROR, + "Inconsistent stream state after decompression: %s", zstr.msg); + /* + * XXX: Intentionally no return. + * + * According to zlib.h, Z_STREAM_ERROR is returned + * "if the stream state was inconsistent". + * + * I assume in this case inflate()'s status + * would also be something different than Z_STREAM_END + * so this check should be redundant, but lets see. + */ + } + + if (status != Z_STREAM_END) + { + /* We failed to decompress the stream. */ + log_error(LOG_LEVEL_ERROR, + "Error in decompressing to the buffer (iob): %s", zstr.msg); + return JB_ERR_COMPRESS; + } + + /* + * Finally, we can actually update the iob, since the + * decompression was successful. First, free the old + * buffer. + */ + freez(csp->iob->buf); + + /* Now, update the iob to use the new buffer. */ + csp->iob->buf = buf; + csp->iob->cur = csp->iob->buf + skip_size; + csp->iob->eod = (char *)zstr.next_out; + csp->iob->size = bufsize; + + /* + * Make sure the new uncompressed iob obeys some minimal + * consistency conditions. + */ + if ((csp->iob->buf < csp->iob->cur) + && (csp->iob->cur <= csp->iob->eod) + && (csp->iob->eod <= csp->iob->buf + csp->iob->size)) + { + const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur); + if (new_size > 0) + { + log_error(LOG_LEVEL_RE_FILTER, + "Decompression successful. Old size: %d, new size: %d.", + old_size, new_size); + } + else + { + /* zlib thinks this is OK, so lets do the same. */ + log_error(LOG_LEVEL_INFO, "Decompression didn't result in any content."); + } + } + else + { + /* It seems that zlib did something weird. */ + log_error(LOG_LEVEL_ERROR, + "Unexpected error decompressing the buffer (iob): %d==%d, %d>%d, %d<%d", + csp->iob->cur, csp->iob->buf + skip_size, csp->iob->eod, csp->iob->buf, + csp->iob->eod, csp->iob->buf + csp->iob->size); + return JB_ERR_COMPRESS; + } + + return JB_ERR_OK; + +} +#endif /* defined(FEATURE_ZLIB) */ + + /********************************************************************* * * Function : get_header @@ -880,6 +1529,36 @@ char *get_header_value(const struct list *header_list, const char *header_name) } + +/********************************************************************* + * + * Function : scan_headers + * + * Description : Scans headers, applies tags and updates action bits. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : JB_ERR_OK + * + *********************************************************************/ +static jb_err scan_headers(struct client_state *csp) +{ + struct list_entry *h; /* Header */ + jb_err err = JB_ERR_OK; + + for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next) + { + /* Header crunch()ed in previous run? -> ignore */ + if (h->str == NULL) continue; + log_error(LOG_LEVEL_HEADER, "scan: %s", h->str); + err = header_tagger(csp, h->str); + } + + return err; +} + + /********************************************************************* * * Function : sed @@ -892,19 +1571,21 @@ char *get_header_value(const struct list *header_list, const char *header_name) * As a side effect it frees the space used by the original * header lines. * + * XXX: should be split to remove the first_run hack. + * * Parameters : * 1 : pats = list of patterns to match against headers * 2 : more_headers = list of functions to add more * headers (client or server) * 3 : csp = Current client state (buffers, headers, etc...) * - * Returns : Single pointer to a fully formed header, or NULL - * on out-of-memory error. + * Returns : JB_ERR_OK in case off success, or + * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -char *sed(const struct parsers pats[], - const add_header_func_ptr more_headers[], - struct client_state *csp) +jb_err sed(const struct parsers pats[], + const add_header_func_ptr more_headers[], + struct client_state *csp) { struct list_entry *p; const struct parsers *v; @@ -920,6 +1601,8 @@ char *sed(const struct parsers pats[], if (first_run) /* Parse and print */ { + scan_headers(csp); + for (v = pats; (err == JB_ERR_OK) && (v->str != NULL) ; v++) { for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL) ; p = p->next) @@ -927,8 +1610,6 @@ char *sed(const struct parsers pats[], /* Header crunch()ed in previous run? -> ignore */ if (p->str == NULL) continue; - if (v == pats) log_error(LOG_LEVEL_HEADER, "scan: %s", p->str); - /* Does the current parser handle this header? */ if ((strncmpic(p->str, v->str, v->len) == 0) || (v->len == CHECK_EVERY_HEADER_REMAINING)) { @@ -950,7 +1631,7 @@ char *sed(const struct parsers pats[], */ if (strncmpic(csp->http->cmd, "HEAD", 4)) { - /*XXX: Code duplication*/ + /*XXX: Code duplication */ for (v = pats; (err == JB_ERR_OK) && (v->str != NULL) ; v++) { for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL) ; p = p->next) @@ -968,75 +1649,223 @@ char *sed(const struct parsers pats[], } } - if (err != JB_ERR_OK) - { - return NULL; - } - - return list_to_text(csp->headers); + return err; } -/* here begins the family of parser functions that reformat header lines */ /********************************************************************* * - * Function : filter_server_header + * Function : header_tagger * - * Description : Checks if server header filtering is enabled. - * If it is, filter_header is called to do the work. + * Description : Executes all text substitutions from applying + * tag actions and saves the result as tag. + * + * XXX: Shares enough code with filter_header() and + * pcrs_filter_response() to warrant some helper functions. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) - * 2 : header = On input, pointer to header to modify. - * On output, pointer to the modified header, or NULL - * to remove the header. This function frees the - * original string if necessary. + * 2 : header = Header that is used as tagger input * * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ -jb_err filter_server_header(struct client_state *csp, char **header) +static jb_err header_tagger(struct client_state *csp, char *header) { - if (csp->action->flags & ACTION_FILTER_SERVER_HEADERS) + int wanted_filter_type; + int multi_action_index; + int i; + pcrs_job *job; + + struct file_list *fl; + struct re_filterfile_spec *b; + struct list_entry *tag_name; + + int found_filters = 0; + const size_t header_length = strlen(header); + + if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) { - filter_header(csp, header); + wanted_filter_type = FT_SERVER_HEADER_TAGGER; + multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER; + } + else + { + wanted_filter_type = FT_CLIENT_HEADER_TAGGER; + multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER; } - return(JB_ERR_OK); -} -/********************************************************************* - * - * Function : filter_client_header - * - * Description : Checks if client header filtering is enabled. - * If it is, filter_header is called to do the work. - * - * Parameters : - * 1 : csp = Current client state (buffers, headers, etc...) - * 2 : header = On input, pointer to header to modify. - * On output, pointer to the modified header, or NULL - * to remove the header. This function frees the - * original string if necessary. - * - * Returns : JB_ERR_OK on success and always succeeds - * - *********************************************************************/ -jb_err filter_client_header(struct client_state *csp, char **header) -{ - if (csp->action->flags & ACTION_FILTER_CLIENT_HEADERS) + /* Check if there are any filters */ + for (i = 0; i < MAX_AF_FILES; i++) + { + fl = csp->rlist[i]; + if (NULL != fl) + { + if (NULL != fl->f) + { + found_filters = 1; + break; + } + } + } + + if (0 == found_filters) { - filter_header(csp, header); + log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: " + "tagging enabled, but no taggers available."); + return(JB_ERR_OK); } - return(JB_ERR_OK); + + for (i = 0; i < MAX_AF_FILES; i++) + { + fl = csp->rlist[i]; + if ((NULL == fl) || (NULL == fl->f)) + { + /* + * Either there are no filter files + * left, or this filter file just + * contains no valid filters. + * + * Continue to be sure we don't miss + * valid filter files that are chained + * after empty or invalid ones. + */ + continue; + } + + /* For all filters, */ + for (b = fl->f; b; b = b->next) + { + if (b->type != wanted_filter_type) + { + /* skip the ones we don't care about, */ + continue; + } + /* leaving only taggers that could apply, of which we use the ones, */ + for (tag_name = csp->action->multi[multi_action_index]->first; + NULL != tag_name; tag_name = tag_name->next) + { + /* that do apply, and */ + if (strcmp(b->name, tag_name->str) == 0) + { + char *modified_tag = NULL; + char *tag = header; + size_t size = header_length; + pcrs_job *joblist = b->joblist; + + if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b); + + if (NULL == joblist) + { + log_error(LOG_LEVEL_RE_FILTER, + "Tagger %s has empty joblist. Nothing to do.", b->name); + continue; + } + + /* execute their pcrs_joblist on the header. */ + for (job = joblist; NULL != job; job = job->next) + { + const int hits = pcrs_execute(job, tag, size, &modified_tag, &size); + + if (0 < hits) + { + /* Success, continue with the modified version. */ + if (tag != header) + { + freez(tag); + } + tag = modified_tag; + } + else + { + /* Tagger doesn't match */ + if (0 > hits) + { + /* Regex failure, log it but continue anyway. */ + log_error(LOG_LEVEL_ERROR, + "Problems with tagger \'%s\' and header \'%s\': %s", + b->name, *header, pcrs_strerror(hits)); + } + freez(modified_tag); + } + } + + if (b->dynamic) pcrs_free_joblist(joblist); + + /* If this tagger matched */ + if (tag != header) + { + if (0 == size) + { + /* + * There is to technical limitation which makes + * it impossible to use empty tags, but I assume + * no one would do it intentionally. + */ + freez(tag); + log_error(LOG_LEVEL_INFO, + "Tagger \'%s\' created an empty tag. Ignored.", + b->name); + continue; + } + + if (!list_contains_item(csp->tags, tag)) + { + if (JB_ERR_OK != enlist(csp->tags, tag)) + { + log_error(LOG_LEVEL_ERROR, + "Insufficient memory to add tag \'%s\', " + "based on tagger \'%s\' and header \'%s\'", + tag, b->name, *header); + } + else + { + char *action_message; + /* + * update the action bits right away, to make + * tagging based on tags set by earlier taggers + * of the same kind possible. + */ + if (update_action_bits_for_tag(csp, tag)) + { + action_message = "Action bits updated accordingly."; + } + else + { + action_message = "No action bits update necessary."; + } + + log_error(LOG_LEVEL_HEADER, + "Tagger \'%s\' added tag \'%s\'. %s", + b->name, tag, action_message); + } + } + else + { + /* XXX: Is this log-worthy? */ + log_error(LOG_LEVEL_HEADER, + "Tagger \'%s\' didn't add tag \'%s\'. " + "Tag already present", b->name, tag); + } + freez(tag); + } /* if the tagger matched */ + } /* if the tagger applies */ + } /* for every tagger that could apply */ + } /* for all filters */ + } /* for all filter files */ + + return JB_ERR_OK; } +/* here begins the family of parser functions that reformat header lines */ + /********************************************************************* * * Function : filter_header * * Description : Executes all text substitutions from all applying - * +filter actions on the header. + * +(server|client)-header-filter actions on the header. * Most of the code was copied from pcrs_filter_response, * including the rather short variable names * @@ -1050,7 +1879,7 @@ jb_err filter_client_header(struct client_state *csp, char **header) * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ -jb_err filter_header(struct client_state *csp, char **header) +static jb_err filter_header(struct client_state *csp, char **header) { int hits=0; int matches; @@ -1064,6 +1893,24 @@ jb_err filter_header(struct client_state *csp, char **header) struct list_entry *filtername; int i, found_filters = 0; + int wanted_filter_type; + int multi_action_index; + + if (csp->flags & CSP_FLAG_NO_FILTERING) + { + return JB_ERR_OK; + } + + if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) + { + wanted_filter_type = FT_SERVER_HEADER_FILTER; + multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER; + } + else + { + wanted_filter_type = FT_CLIENT_HEADER_FILTER; + multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER; + } /* * Need to check the set of re_filterfiles... @@ -1083,15 +1930,27 @@ jb_err filter_header(struct client_state *csp, char **header) if (0 == found_filters) { - log_error(LOG_LEVEL_ERROR, "Unable to get current state of regexp filtering."); - return(JB_ERR_OK); + log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: " + "header filtering enabled, but no matching filters available."); + return(JB_ERR_OK); } for (i = 0; i < MAX_AF_FILES; i++) { fl = csp->rlist[i]; if ((NULL == fl) || (NULL == fl->f)) - break; + { + /* + * Either there are no filter files + * left, or this filter file just + * contains no valid filters. + * + * Continue to be sure we don't miss + * valid filter files that are chained + * after empty or invalid ones. + */ + continue; + } /* * For all applying +filter actions, look if a filter by that * name exists and if yes, execute its pcrs_joblist on the @@ -1099,24 +1958,33 @@ jb_err filter_header(struct client_state *csp, char **header) */ for (b = fl->f; b; b = b->next) { - for (filtername = csp->action->multi[ACTION_MULTI_FILTER]->first; + if (b->type != wanted_filter_type) + { + /* Skip other filter types */ + continue; + } + + for (filtername = csp->action->multi[multi_action_index]->first; filtername ; filtername = filtername->next) { if (strcmp(b->name, filtername->str) == 0) { int current_hits = 0; + pcrs_job *joblist = b->joblist; + + if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b); - if ( NULL == b->joblist ) + if (NULL == joblist) { log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name); continue; } - log_error(LOG_LEVEL_RE_FILTER, "re_filtering %s (size %d) with filter %s...", + log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %d) with \'%s\' ...", *header, size, b->name); /* Apply all jobs from the joblist */ - for (job = b->joblist; NULL != job; job = job->next) + for (job = joblist; NULL != job; job = job->next) { matches = pcrs_execute(job, *header, size, &newheader, &size); if ( 0 < matches ) @@ -1136,21 +2004,29 @@ jb_err filter_header(struct client_state *csp, char **header) /* RegEx failure */ log_error(LOG_LEVEL_ERROR, "Filtering \'%s\' with \'%s\' didn't work out: %s", *header, b->name, pcrs_strerror(matches)); - if( newheader != NULL) + if (newheader != NULL) { log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader); freez(newheader); } } } - log_error(LOG_LEVEL_RE_FILTER, " ...produced %d hits (new size %d).", current_hits, size); + + if (b->dynamic) pcrs_free_joblist(joblist); + + log_error(LOG_LEVEL_RE_FILTER, "... produced %d hits (new size %d).", current_hits, size); hits += current_hits; } } } } - if ( 0 == size ) + /* + * Additionally checking for hits is important because if + * the continue hack is triggered, server headers can + * arrive empty to separate multiple heads from each other. + */ + if ((0 == size) && hits) { log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header); freez(*header); @@ -1160,6 +2036,56 @@ jb_err filter_header(struct client_state *csp, char **header) } +/********************************************************************* + * + * Function : connection + * + * Description : Makes sure that the value of the Connection: header + * is "close" and signals connection_close_adder + * to do nothing. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : header = On input, pointer to header to modify. + * On output, pointer to the modified header, or NULL + * to remove the header. This function frees the + * original string if necessary. + * + * Returns : JB_ERR_OK on success, or + * JB_ERR_MEMORY on out-of-memory error. + * + *********************************************************************/ +static jb_err connection(struct client_state *csp, char **header) +{ + char *old_header = *header; + + /* Do we have a 'Connection: close' header? */ + if (strcmpic(*header, "Connection: close")) + { + /* No, create one */ + *header = strdup("Connection: close"); + if (header == NULL) + { + return JB_ERR_MEMORY; + } + log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header); + freez(old_header); + } + + /* Signal connection_close_adder() to return early. */ + if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) + { + csp->flags |= CSP_FLAG_SERVER_CONNECTION_CLOSE_SET; + } + else + { + csp->flags |= CSP_FLAG_CLIENT_CONNECTION_CLOSE_SET; + } + + return JB_ERR_OK; +} + + /********************************************************************* * * Function : crumble @@ -1177,13 +2103,14 @@ jb_err filter_header(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err crumble(struct client_state *csp, char **header) +static jb_err crumble(struct client_state *csp, char **header) { log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header); freez(*header); return JB_ERR_OK; } + /********************************************************************* * * Function : crunch_server_header @@ -1201,16 +2128,16 @@ jb_err crumble(struct client_state *csp, char **header) * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ -jb_err crunch_server_header(struct client_state *csp, char **header) +static jb_err crunch_server_header(struct client_state *csp, char **header) { const char *crunch_pattern; - /*Is there a header to crunch*/ + /* Do we feel like crunching? */ if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER)) { crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER]; - /*Is the current header the lucky one?*/ + /* Is the current header the lucky one? */ if (strstr(*header, crunch_pattern)) { log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern); @@ -1220,12 +2147,14 @@ jb_err crunch_server_header(struct client_state *csp, char **header) return JB_ERR_OK; } + + /********************************************************************* * * Function : server_content_type * * Description : Set the content-type for filterable types (text/.*, - * javascript and image/gif) unless filtering has been + * .*xml.*, javascript and image/gif) unless filtering has been * forbidden (CT_TABOO) while parsing earlier headers. * NOTE: Since text/plain is commonly used by web servers * for files whose correct type is unknown, we don't @@ -1242,71 +2171,79 @@ jb_err crunch_server_header(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_content_type(struct client_state *csp, char **header) +static jb_err server_content_type(struct client_state *csp, char **header) { - const char *newval; - - newval = csp->action->string[ACTION_STRING_CONTENT_TYPE]; - - if (csp->content_type != CT_TABOO) - { - if ((strstr(*header, " text/") && !strstr(*header, "plain")) - || strstr(*header, "xml") - || strstr(*header, "application/x-javascript")) - csp->content_type = CT_TEXT; - else if (strstr(*header, " image/gif")) - csp->content_type = CT_GIF; - else if (strstr(*header, " image/jpeg")) - csp->content_type = CT_JPEG; - else - csp->content_type = 0; + /* Remove header if it isn't the first Content-Type header */ + if ((csp->content_type & CT_DECLARED)) + { + /* + * Another, slightly slower, way to see if + * we already parsed another Content-Type header. + */ + assert(NULL != get_header_value(csp->headers, "Content-Type:")); + + log_error(LOG_LEVEL_ERROR, + "Multiple Content-Type headers. Removing and ignoring: \'%s\'", + *header); + freez(*header); + + return JB_ERR_OK; } + /* - * Are we enabling text mode by force? + * Signal that the Content-Type has been set. */ - if (csp->action->flags & ACTION_FORCE_TEXT_MODE) + csp->content_type |= CT_DECLARED; + + if (!(csp->content_type & CT_TABOO)) { - /* - * Do we really have to? - */ - if (csp->content_type == CT_TEXT) + /* + * XXX: The assumption that text/plain is a sign of + * binary data seems to be somewhat unreasonable nowadays + * and should be dropped after 3.0.8 is out. + */ + if ((strstr(*header, "text/") && !strstr(*header, "plain")) + || strstr(*header, "xml") + || strstr(*header, "application/x-javascript")) { - log_error(LOG_LEVEL_HEADER, "Text mode is already enabled."); + csp->content_type |= CT_TEXT; } - else + else if (strstr(*header, "image/gif")) { - csp->content_type = CT_TEXT; - log_error(LOG_LEVEL_HEADER, "Text mode enabled by force. Take cover!"); + csp->content_type |= CT_GIF; } } + /* * Are we messing with the content type? - */ + */ if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE) - { - /* - * Make sure the user doesn't accidently - * change the content type of binary documents. - */ - if (csp->content_type == CT_TEXT) - { - freez(*header); - *header = strdup("Content-Type: "); - string_append(header, newval); - - if (header == NULL) - { - log_error(LOG_LEVEL_HEADER, "Insufficient memory. Conten-Type crunched without replacement!"); - return JB_ERR_MEMORY; - } - log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header); - } - else - { - log_error(LOG_LEVEL_HEADER, "%s not replaced. It doesn't look like text. " - "Enable force-text-mode if you know what you're doing.", *header); - } - } + { + /* + * Make sure the user doesn't accidently + * change the content type of binary documents. + */ + if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE)) + { + freez(*header); + *header = strdup("Content-Type: "); + string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]); + + if (header == NULL) + { + log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!"); + return JB_ERR_MEMORY; + } + log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header); + } + else + { + log_error(LOG_LEVEL_HEADER, "%s not replaced. " + "It doesn't look like a content type that should be filtered. " + "Enable force-text-mode if you know what you're doing.", *header); + } + } + return JB_ERR_OK; } @@ -1331,13 +2268,20 @@ jb_err server_content_type(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_transfer_coding(struct client_state *csp, char **header) +static jb_err server_transfer_coding(struct client_state *csp, char **header) { /* * Turn off pcrs and gif filtering if body compressed */ if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate")) { +#ifdef FEATURE_ZLIB + /* + * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here. + */ + log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.", + csp->http->cmd, *header); +#endif /* def FEATURE_ZLIB */ csp->content_type = CT_TABOO; } @@ -1350,7 +2294,10 @@ jb_err server_transfer_coding(struct client_state *csp, char **header) /* * If the body was modified, it has been de-chunked first - * and the header must be removed. + * and the header must be removed. + * + * FIXME: If there is more than one transfer encoding, + * only the "chunked" part should be removed here. */ if (csp->flags & CSP_FLAG_MODIFIED) { @@ -1367,7 +2314,16 @@ jb_err server_transfer_coding(struct client_state *csp, char **header) * * Function : server_content_encoding * - * Description : Prohibit filtering (CT_TABOO) if content encoding compresses + * Description : This function is run twice for each request, + * unless FEATURE_ZLIB and filtering are disabled. + * + * The first run is used to check if the content + * is compressed, if FEATURE_ZLIB is disabled + * filtering is then disabled as well, if FEATURE_ZLIB + * is enabled the content is marked for decompression. + * + * The second run is used to remove the Content-Encoding + * header if the decompression was successful. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -1380,15 +2336,62 @@ jb_err server_transfer_coding(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_content_encoding(struct client_state *csp, char **header) +static jb_err server_content_encoding(struct client_state *csp, char **header) { - /* - * Turn off pcrs and gif filtering if body compressed - */ +#ifdef FEATURE_ZLIB + if ((csp->flags & CSP_FLAG_MODIFIED) + && (csp->content_type & (CT_GZIP | CT_DEFLATE))) + { + /* + * We successfully decompressed the content, + * and have to clean the header now, so the + * client no longer expects compressed data.. + * + * XXX: There is a difference between cleaning + * and removing it completely. + */ + log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header); + freez(*header); + } + else if (strstr(*header, "gzip")) + { + /* Mark for gzip decompression */ + csp->content_type |= CT_GZIP; + } + else if (strstr(*header, "deflate")) + { + /* Mark for zlib decompression */ + csp->content_type |= CT_DEFLATE; + } + else if (strstr(*header, "compress")) + { + /* + * We can't decompress this; therefore we can't filter + * it either. + */ + csp->content_type |= CT_TABOO; + } +#else /* !defined(FEATURE_ZLIB) */ if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate")) { - csp->content_type = CT_TABOO; + /* + * Body is compressed, turn off pcrs and gif filtering. + */ + csp->content_type |= CT_TABOO; + + /* + * Log a warning if the user expects the content to be filtered. + */ + if ((csp->rlist != NULL) && + (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER]))) + { + log_error(LOG_LEVEL_INFO, + "Compressed content detected, content filtering disabled. " + "Consider recompiling Privoxy with zlib support or " + "enable the prevent-compression action."); + } } +#endif /* defined(FEATURE_ZLIB) */ return JB_ERR_OK; @@ -1413,24 +2416,24 @@ jb_err server_content_encoding(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_content_length(struct client_state *csp, char **header) +static jb_err server_content_length(struct client_state *csp, char **header) { - if (csp->content_length != 0) /* Content length could have been modified */ + const size_t max_header_length = 80; + + /* Regenerate header if the content was modified. */ + if (csp->flags & CSP_FLAG_MODIFIED) { - /* - * XXX: Shouldn't we check if csp->content_length - * is different than the original value? - */ freez(*header); - *header = (char *) zalloc(100); + *header = (char *) zalloc(max_header_length); if (*header == NULL) { return JB_ERR_MEMORY; } - sprintf(*header, "Content-Length: %d", (int) csp->content_length); - - log_error(LOG_LEVEL_HEADER, "Adjust Content-Length to %d", (int) csp->content_length); + snprintf(*header, max_header_length, "Content-Length: %d", + (int)csp->content_length); + log_error(LOG_LEVEL_HEADER, "Adjusted Content-Length to %d", + (int)csp->content_length); } return JB_ERR_OK; @@ -1455,7 +2458,7 @@ jb_err server_content_length(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_content_md5(struct client_state *csp, char **header) +static jb_err server_content_md5(struct client_state *csp, char **header) { if (csp->flags & CSP_FLAG_MODIFIED) { @@ -1466,11 +2469,12 @@ jb_err server_content_md5(struct client_state *csp, char **header) return JB_ERR_OK; } + /********************************************************************* * * Function : server_content_disposition * - * Description : If enabled, blocks or modifies the "content-disposition" header. + * Description : If enabled, blocks or modifies the "Content-Disposition" header. * Called from `sed'. * * Parameters : @@ -1484,22 +2488,22 @@ jb_err server_content_md5(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_content_disposition(struct client_state *csp, char **header) +static jb_err server_content_disposition(struct client_state *csp, char **header) { const char *newval; /* - * Are we messing with the content-disposition header? + * Are we messing with the Content-Disposition header? */ if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0) { - /*Me tinks not*/ + /* Me tinks not */ return JB_ERR_OK; } newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION]; - if ((newval == NULL) || (0 == strcmpic(newval, "block")) ) + if ((newval == NULL) || (0 == strcmpic(newval, "block"))) { /* * Blocking content-disposition header @@ -1511,24 +2515,22 @@ jb_err server_content_disposition(struct client_state *csp, char **header) else { /* - * Replacing content-disposition header + * Replacing Content-Disposition header */ freez(*header); - *header = strdup("content-disposition: "); - string_append(header, newval); + *header = strdup("Content-Disposition: "); + string_append(header, newval); - if (*header == NULL) - { - log_error(LOG_LEVEL_HEADER, "Insufficent memory. content-disposition header not fully replaced."); - } - else + if (*header != NULL) { - log_error(LOG_LEVEL_HEADER, "content-disposition header crunched and replaced with: %s", *header); + log_error(LOG_LEVEL_HEADER, + "Content-Disposition header crunched and replaced with: %s", *header); } } return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } + /********************************************************************* * * Function : server_last_modified @@ -1548,7 +2550,7 @@ jb_err server_content_disposition(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_last_modified(struct client_state *csp, char **header) +static jb_err server_last_modified(struct client_state *csp, char **header) { const char *newval; char buf[BUFFER_SIZE]; @@ -1603,6 +2605,8 @@ jb_err server_last_modified(struct client_state *csp, char **header) } else if (0 == strcmpic(newval, "randomize")) { + const char *header_time = *header + sizeof("Last-Modified:"); + log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header); now = time(NULL); #ifdef HAVE_GMTIME_R @@ -1614,9 +2618,9 @@ jb_err server_last_modified(struct client_state *csp, char **header) #else timeptr = gmtime(&now); #endif - if ((timeptr = parse_header_time(*header, &last_modified)) == NULL) + if (JB_ERR_OK != parse_header_time(header_time, &last_modified)) { - log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s (crunching!)", *header); + log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s in %s (crunching!)", header_time, *header); freez(*header); } else @@ -1624,7 +2628,16 @@ jb_err server_last_modified(struct client_state *csp, char **header) rtime = (long int)difftime(now, last_modified); if (rtime) { + int negative = 0; + + if (rtime < 0) + { + rtime *= -1; + negative = 1; + log_error(LOG_LEVEL_HEADER, "Server time in the future."); + } rtime = pick_from_range(rtime); + if (negative) rtime *= -1; last_modified += rtime; #ifdef HAVE_GMTIME_R timeptr = gmtime_r(&last_modified, &gmt); @@ -1646,7 +2659,7 @@ jb_err server_last_modified(struct client_state *csp, char **header) return JB_ERR_MEMORY; } - if(LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ + if (LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ { days = rtime / (3600 * 24); hours = rtime / 3600 % 24; @@ -1668,6 +2681,7 @@ jb_err server_last_modified(struct client_state *csp, char **header) return JB_ERR_OK; } + /********************************************************************* * * Function : client_accept_encoding @@ -1687,7 +2701,7 @@ jb_err server_last_modified(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_accept_encoding(struct client_state *csp, char **header) +static jb_err client_accept_encoding(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) { @@ -1732,7 +2746,7 @@ jb_err client_accept_encoding(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_te(struct client_state *csp, char **header) +static jb_err client_te(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) { @@ -1743,6 +2757,7 @@ jb_err client_te(struct client_state *csp, char **header) return JB_ERR_OK; } + /********************************************************************* * * Function : client_referrer @@ -1761,115 +2776,67 @@ jb_err client_te(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_referrer(struct client_state *csp, char **header) +static jb_err client_referrer(struct client_state *csp, char **header) { - const char *newval; - const char *host; - char *referer; - size_t hostlenght; + const char *parameter; + /* booleans for parameters we have to check multiple times */ + int parameter_conditional_block; + int parameter_conditional_forge; #ifdef FEATURE_FORCE_LOAD - /* Since the referrer can include the prefix even + /* + * Since the referrer can include the prefix even * if the request itself is non-forced, we must - * clean it unconditionally + * clean it unconditionally. + * + * XXX: strclean is too broad */ strclean(*header, FORCE_PREFIX); #endif /* def FEATURE_FORCE_LOAD */ - /* - * Are we sending referer? - */ if ((csp->action->flags & ACTION_HIDE_REFERER) == 0) - { - return JB_ERR_OK; - } - - newval = csp->action->string[ACTION_STRING_REFERER]; - - if ((0 != strcmpic(newval, "conditional-block"))) - { - freez(*header); - } - if ((newval == NULL) || (0 == strcmpic(newval, "block")) ) - { - /* - * Blocking referer - */ - log_error(LOG_LEVEL_HEADER, "Referer crunched!"); - return JB_ERR_OK; - } - else if (0 == strcmpic(newval, "conditional-block")) - { - /* - * Block referer if host has changed. - */ - - if (NULL == (host = strdup(csp->http->hostport))) - { - freez(*header); - log_error(LOG_LEVEL_HEADER, "Referer crunched! Couldn't allocate memory for temporary host copy."); - return JB_ERR_MEMORY; - } - if (NULL == (referer = strdup(*header))) - { - freez(*header); - freez(host); - log_error(LOG_LEVEL_HEADER, "Referer crunched! Couldn't allocate memory for temporary referer copy."); - return JB_ERR_MEMORY; - } - hostlenght = strlen(host); - if ( hostlenght < (strlen(referer)-17) ) /*referer begins with 'Referer: http[s]://'*/ - { - /*Shorten referer to make sure the referer is blocked - *if www.example.org/www.example.com-shall-see-the-referer/ - *links to www.example.com/ - */ - referer[hostlenght+17] = '\0'; - } - if ( 0 == strstr(referer, host)) /*Host has changed*/ - { - log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header); - freez(*header); - } - else - { - log_error(LOG_LEVEL_HEADER, "%s (not modified, still on %s)", *header, host); - } - freez(referer); - freez(host); - return JB_ERR_OK; + { + /* Nothing left to do */ + return JB_ERR_OK; } - else if (0 != strcmpic(newval, "forge")) + + parameter = csp->action->string[ACTION_STRING_REFERER]; + assert(parameter != NULL); + parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block")); + parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge")); + + if (!parameter_conditional_block && !parameter_conditional_forge) { /* - * We have a specific (fixed) referer we want to send. + * As conditional-block and conditional-forge are the only + * parameters that rely on the original referrer, we can + * remove it now for all the others. */ - if ((0 != strncmpic(newval, "http://", 7)) && (0 != strncmpic(newval, "https://", 8))) - { - log_error(LOG_LEVEL_HEADER, "Parameter: +referrer{%s} is a bad idea, but I don't care.", newval); - } - *header = strdup("Referer: "); - string_append(header, newval); - log_error(LOG_LEVEL_HEADER, "Referer overwritten with: %s", *header); + freez(*header); + } - return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; + if (0 == strcmpic(parameter, "block")) + { + log_error(LOG_LEVEL_HEADER, "Referer crunched!"); + return JB_ERR_OK; + } + else if (parameter_conditional_block || parameter_conditional_forge) + { + return handle_conditional_hide_referrer_parameter(header, + csp->http->hostport, parameter_conditional_block); + } + else if (0 == strcmpic(parameter, "forge")) + { + return create_forged_referrer(header, csp->http->hostport); } else { - /* - * Forge a referer as http://[hostname:port of REQUEST]/ - * to fool stupid checks for in-site links - */ - - *header = strdup("Referer: http://"); - string_append(header, csp->http->hostport); - string_append(header, "/"); - log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header); - - return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; + /* interpret parameter as user-supplied referer to fake */ + return create_fake_referrer(header, parameter); } } + /********************************************************************* * * Function : client_accept_language @@ -1888,7 +2855,7 @@ jb_err client_referrer(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_accept_language(struct client_state *csp, char **header) +static jb_err client_accept_language(struct client_state *csp, char **header) { const char *newval; @@ -1923,16 +2890,19 @@ jb_err client_accept_language(struct client_state *csp, char **header) if (*header == NULL) { - log_error(LOG_LEVEL_ERROR, " Insufficent memory. Accept-Language header crunched without replacement."); + log_error(LOG_LEVEL_ERROR, + "Insufficent memory. Accept-Language header crunched without replacement."); } else { - log_error(LOG_LEVEL_HEADER, "Accept-Language header crunched and replaced with: %s", *header); + log_error(LOG_LEVEL_HEADER, + "Accept-Language header crunched and replaced with: %s", *header); } } return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } + /********************************************************************* * * Function : crunch_client_header @@ -1950,16 +2920,16 @@ jb_err client_accept_language(struct client_state *csp, char **header) * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ -jb_err crunch_client_header(struct client_state *csp, char **header) +static jb_err crunch_client_header(struct client_state *csp, char **header) { const char *crunch_pattern; - /*Is there a header to crunch*/ - + + /* Do we feel like crunching? */ if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER)) { crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER]; - /*Is the current header the lucky one?*/ + /* Is the current header the lucky one? */ if (strstr(*header, crunch_pattern)) { log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern); @@ -1989,7 +2959,7 @@ jb_err crunch_client_header(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_uagent(struct client_state *csp, char **header) +static jb_err client_uagent(struct client_state *csp, char **header) { const char *newval; @@ -2013,6 +2983,7 @@ jb_err client_uagent(struct client_state *csp, char **header) return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } + /********************************************************************* * * Function : client_ua @@ -2030,7 +3001,7 @@ jb_err client_uagent(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_ua(struct client_state *csp, char **header) +static jb_err client_ua(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0) { @@ -2060,7 +3031,7 @@ jb_err client_ua(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_from(struct client_state *csp, char **header) +static jb_err client_from(struct client_state *csp, char **header) { const char *newval; @@ -2095,9 +3066,10 @@ jb_err client_from(struct client_state *csp, char **header) * * Function : client_send_cookie * - * Description : Handle the "cookie" header properly. Called from `sed'. - * If cookie is accepted, add it to the cookie_list, - * else we crunch it. Mmmmmmmmmmm ... cookie ...... + * Description : Crunches the "cookie" header if necessary. + * Called from `sed'. + * + * XXX: Stupid name, doesn't send squat. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -2110,27 +3082,15 @@ jb_err client_from(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_send_cookie(struct client_state *csp, char **header) +static jb_err client_send_cookie(struct client_state *csp, char **header) { - jb_err result = JB_ERR_OK; - - if ((csp->action->flags & ACTION_NO_COOKIE_READ) == 0) + if (csp->action->flags & ACTION_NO_COOKIE_READ) { - /* strlen("cookie: ") == 8 */ - result = enlist(csp->cookie_list, *header + 8); - } - else - { - log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie -- yum!"); + log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header); + freez(*header); } - /* - * Always remove the cookie here. The cookie header - * will be sent at the end of the header. - */ - freez(*header); - - return result; + return JB_ERR_OK; } @@ -2154,19 +3114,7 @@ jb_err client_send_cookie(struct client_state *csp, char **header) *********************************************************************/ jb_err client_x_forwarded(struct client_state *csp, char **header) { - if ((csp->action->flags & ACTION_HIDE_FORWARDED) == 0) - { - /* Save it so we can re-add it later */ - freez(csp->x_forwarded); - csp->x_forwarded = *header; - - /* - * Always set *header = NULL, since this information - * will be sent at the end of the header. - */ - *header = NULL; - } - else + if ((csp->action->flags & ACTION_HIDE_FORWARDED) != 0) { freez(*header); log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!"); @@ -2194,25 +3142,33 @@ jb_err client_x_forwarded(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_max_forwards(struct client_state *csp, char **header) +static jb_err client_max_forwards(struct client_state *csp, char **header) { - unsigned int max_forwards; + int max_forwards; - if ((0 == strcmpic(csp->http->gpc, "trace")) - || (0 == strcmpic(csp->http->gpc, "options"))) + if ((0 == strcmpic(csp->http->gpc, "trace")) || + (0 == strcmpic(csp->http->gpc, "options"))) { - if (1 == sscanf(*header, "Max-Forwards: %u", &max_forwards)) + assert(*(*header+12) == ':'); + if (1 == sscanf(*header+12, ": %u", &max_forwards)) { - if (max_forwards-- >= 1) + if (max_forwards > 0) { - sprintf(*header, "Max-Forwards: %u", max_forwards); - log_error(LOG_LEVEL_HEADER, "Max forwards of %s request now %d", csp->http->gpc, max_forwards); + snprintf(*header, strlen(*header)+1, "Max-Forwards: %u", --max_forwards); + log_error(LOG_LEVEL_HEADER, "Max-Forwards value for %s request reduced to %u.", + csp->http->gpc, max_forwards); } - else + else if (max_forwards < 0) { - log_error(LOG_LEVEL_ERROR, "Non-intercepted %s request with Max-Forwards zero!", csp->http->gpc); + log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header); + freez(*header); } } + else + { + log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header); + freez(*header); + } } return JB_ERR_OK; @@ -2241,7 +3197,7 @@ jb_err client_max_forwards(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_host(struct client_state *csp, char **header) +static jb_err client_host(struct client_state *csp, char **header) { char *p, *q; @@ -2292,9 +3248,13 @@ jb_err client_host(struct client_state *csp, char **header) csp->http->hostport, csp->http->host, csp->http->port); } + /* Signal client_host_adder() to return right away */ + csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET; + return JB_ERR_OK; } + /********************************************************************* * * Function : client_if_modified_since @@ -2312,7 +3272,7 @@ jb_err client_host(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_if_modified_since(struct client_state *csp, char **header) +static jb_err client_if_modified_since(struct client_state *csp, char **header) { char newheader[50]; #ifdef HAVE_GMTIME_R @@ -2349,19 +3309,21 @@ jb_err client_if_modified_since(struct client_state *csp, char **header) } else /* add random value */ { - if ((timeptr = parse_header_time(*header, &tm)) == NULL) + const char *header_time = *header + sizeof("If-Modified-Since:"); + + if (JB_ERR_OK != parse_header_time(header_time, &tm)) { - log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s (crunching!)", *header); + log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s in %s (crunching!)", header_time, *header); freez(*header); } else { rtime = strtol(newval, &endptr, 0); - if(rtime) + if (rtime) { log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %d minut%s)", *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es"); - if(rtime < 0) + if (rtime < 0) { rtime *= -1; negative = 1; @@ -2396,7 +3358,7 @@ jb_err client_if_modified_since(struct client_state *csp, char **header) return JB_ERR_MEMORY; } - if(LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ + if (LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ { hours = rtime / 3600; minutes = rtime / 60 % 60; @@ -2413,6 +3375,7 @@ jb_err client_if_modified_since(struct client_state *csp, char **header) return JB_ERR_OK; } + /********************************************************************* * * Function : client_if_none_match @@ -2430,7 +3393,7 @@ jb_err client_if_modified_since(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_if_none_match(struct client_state *csp, char **header) +static jb_err client_if_none_match(struct client_state *csp, char **header) { if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH) { @@ -2441,6 +3404,7 @@ jb_err client_if_none_match(struct client_state *csp, char **header) return JB_ERR_OK; } + /********************************************************************* * * Function : client_x_filter @@ -2470,13 +3434,13 @@ jb_err client_x_filter(struct client_state *csp, char **header) { if (csp->action->flags & ACTION_FORCE_TEXT_MODE) { - log_error(LOG_LEVEL_HEADER, "force-text-mode overruled the client's request to fetch without filtering!"); + log_error(LOG_LEVEL_HEADER, + "force-text-mode overruled the client's request to fetch without filtering!"); } else { - csp->content_type = CT_TABOO; - csp->action->flags &= ~ACTION_FILTER_SERVER_HEADERS; - csp->action->flags &= ~ACTION_FILTER_CLIENT_HEADERS; + csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */ + csp->flags |= CSP_FLAG_NO_FILTERING; log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering."); } log_error(LOG_LEVEL_HEADER, "Crunching %s", *header); @@ -2486,6 +3450,40 @@ jb_err client_x_filter(struct client_state *csp, char **header) return JB_ERR_OK; } + +/********************************************************************* + * + * Function : client_range + * + * Description : Removes Range, Request-Range and If-Range headers if + * content filtering is enabled. If the client's version + * of the document has been altered by Privoxy, the server + * could interpret the range differently than the client + * intended in which case the user could end up with + * corrupted content. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : header = On input, pointer to header to modify. + * On output, pointer to the modified header, or NULL + * to remove the header. This function frees the + * original string if necessary. + * + * Returns : JB_ERR_OK + * + *********************************************************************/ +static jb_err client_range(struct client_state *csp, char **header) +{ + if (content_filters_enabled(csp)) + { + log_error(LOG_LEVEL_HEADER, "Content filtering is enabled." + " Crunching: \'%s\' to prevent range-mismatch problems.", *header); + freez(*header); + } + + return JB_ERR_OK; +} + /* the following functions add headers directly to the header list */ /********************************************************************* @@ -2502,13 +3500,21 @@ jb_err client_x_filter(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_host_adder(struct client_state *csp) +static jb_err client_host_adder(struct client_state *csp) { char *p; jb_err err; + if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET) + { + /* Header already set by the client, nothing to do. */ + return JB_ERR_OK; + } + if ( !csp->http->hostport || !*(csp->http->hostport)) { + /* XXX: When does this happen and why is it OK? */ + log_error(LOG_LEVEL_INFO, "Weirdness in client_host_adder detected and ignored."); return JB_ERR_OK; } @@ -2524,6 +3530,7 @@ jb_err client_host_adder(struct client_state *csp) p = csp->http->hostport; } + /* XXX: Just add it, we already made sure that it will be unique */ log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p); err = enlist_unique_header(csp->headers, "Host", p); return err; @@ -2535,7 +3542,8 @@ jb_err client_host_adder(struct client_state *csp) * * Function : client_cookie_adder * - * Description : Used in the add_client_headers list. Called from `sed'. + * Description : Used in the add_client_headers list to add "wafers". + * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -2546,45 +3554,39 @@ jb_err client_host_adder(struct client_state *csp) *********************************************************************/ jb_err client_cookie_adder(struct client_state *csp) { - struct list_entry *lst; char *tmp; - struct list_entry *list1 = csp->cookie_list->first; - struct list_entry *list2 = csp->action->multi[ACTION_MULTI_WAFER]->first; - int first_cookie = 1; + struct list_entry *wafer; + struct list_entry *wafer_list; jb_err err; - if ((list1 == NULL) && (list2 == NULL)) + /* + * If the user has not supplied any wafers, and the user has not + * told us to suppress the vanilla wafer, then send the vanilla wafer. + */ + if ((0 != (csp->action->flags & ACTION_VANILLA_WAFER)) + && list_is_empty(csp->action->multi[ACTION_MULTI_WAFER])) { - /* Nothing to do */ - return JB_ERR_OK; + enlist(csp->action->multi[ACTION_MULTI_WAFER], VANILLA_WAFER); } - tmp = strdup("Cookie: "); + wafer_list = csp->action->multi[ACTION_MULTI_WAFER]->first; - for (lst = list1; lst ; lst = lst->next) + if (NULL == wafer_list) { - if (first_cookie) - { - first_cookie = 0; - } - else - { - string_append(&tmp, "; "); - } - string_append(&tmp, lst->str); + /* Nothing to do */ + return JB_ERR_OK; } - for (lst = list2; lst ; lst = lst->next) + tmp = strdup("Cookie: "); + + for (wafer = wafer_list; (NULL != tmp) && (NULL != wafer); wafer = wafer->next) { - if (first_cookie) - { - first_cookie = 0; - } - else + if (wafer != wafer_list) { + /* As this isn't the first wafer, we need a delimiter. */ string_append(&tmp, "; "); } - string_join(&tmp, cookie_encode(lst->str)); + string_join(&tmp, cookie_encode(wafer->str)); } if (tmp == NULL) @@ -2599,6 +3601,7 @@ jb_err client_cookie_adder(struct client_state *csp) } +#if 0 /********************************************************************* * * Function : client_accept_encoding_adder @@ -2615,7 +3618,7 @@ jb_err client_cookie_adder(struct client_state *csp) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_accept_encoding_adder(struct client_state *csp) +static jb_err client_accept_encoding_adder(struct client_state *csp) { if ( ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) && (!strcmpic(csp->http->ver, "HTTP/1.1")) ) @@ -2625,6 +3628,7 @@ jb_err client_accept_encoding_adder(struct client_state *csp) return JB_ERR_OK; } +#endif /********************************************************************* @@ -2640,7 +3644,7 @@ jb_err client_accept_encoding_adder(struct client_state *csp) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_xtra_adder(struct client_state *csp) +static jb_err client_xtra_adder(struct client_state *csp) { struct list_entry *lst; jb_err err; @@ -2663,9 +3667,13 @@ jb_err client_xtra_adder(struct client_state *csp) /********************************************************************* * - * Function : client_x_forwarded_adder + * Function : connection_close_adder + * + * Description : "Temporary" fix for the needed but missing HTTP/1.1 + * support. Adds a "Connection: close" header to csp->headers + * unless the header was already present. Called from `sed'. * - * Description : Used in the add_client_headers list. Called from `sed'. + * FIXME: This whole function shouldn't be neccessary! * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -2674,59 +3682,29 @@ jb_err client_xtra_adder(struct client_state *csp) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err client_x_forwarded_adder(struct client_state *csp) +static jb_err connection_close_adder(struct client_state *csp) { - char *p = NULL; - jb_err err; + const unsigned int flags = csp->flags; - if ((csp->action->flags & ACTION_HIDE_FORWARDED) != 0) + /* + * Return right away if + * + * - we're parsing server headers and the server header + * "Connection: close" is already set, or if + * + * - we're parsing client headers and the client header + * "Connection: close" is already set. + */ + if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE + && flags & CSP_FLAG_SERVER_CONNECTION_CLOSE_SET) + ||(!(flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) + && flags & CSP_FLAG_CLIENT_CONNECTION_CLOSE_SET)) { return JB_ERR_OK; } - if (csp->x_forwarded) - { - p = strdup(csp->x_forwarded); - string_append(&p, ", "); - } - else - { - p = strdup("X-Forwarded-For: "); - } - string_append(&p, csp->ip_addr_str); - - if (p == NULL) - { - return JB_ERR_MEMORY; - } - - log_error(LOG_LEVEL_HEADER, "addh: %s", p); - err = enlist(csp->headers, p); - free(p); - - return err; -} - - -/********************************************************************* - * - * Function : connection_close_adder - * - * Description : Adds a "Connection: close" header to csp->headers - * as a temporary fix for the needed but missing HTTP/1.1 - * support. Called from `sed'. - * FIXME: This whole function shouldn't be neccessary! - * - * Parameters : - * 1 : csp = Current client state (buffers, headers, etc...) - * - * Returns : JB_ERR_OK on success, or - * JB_ERR_MEMORY on out-of-memory error. - * - *********************************************************************/ -jb_err connection_close_adder(struct client_state *csp) -{ log_error(LOG_LEVEL_HEADER, "Adding: Connection: close"); + return enlist(csp->headers, "Connection: close"); } @@ -2752,7 +3730,7 @@ jb_err connection_close_adder(struct client_state *csp) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_http(struct client_state *csp, char **header) +static jb_err server_http(struct client_state *csp, char **header) { sscanf(*header, "HTTP/%*d.%*d %d", &(csp->http->status)); if (csp->http->status == 206) @@ -2762,8 +3740,21 @@ jb_err server_http(struct client_state *csp, char **header) if ((csp->action->flags & ACTION_DOWNGRADE) != 0) { - (*header)[7] = '0'; - log_error(LOG_LEVEL_HEADER, "Downgraded answer to HTTP/1.0"); + /* XXX: Should we do a real validity check here? */ + if (strlen(*header) > 8) + { + (*header)[7] = '0'; + log_error(LOG_LEVEL_HEADER, "Downgraded answer to HTTP/1.0"); + } + else + { + /* + * XXX: Should we block the request or + * enlist a valid status code line here? + */ + log_error(LOG_LEVEL_INFO, "Malformed server response detected. " + "Downgrading to HTTP/1.0 impossible."); + } } return JB_ERR_OK; @@ -2775,8 +3766,13 @@ jb_err server_http(struct client_state *csp, char **header) * Function : server_set_cookie * * Description : Handle the server "cookie" header properly. - * Log cookie to the jar file. Then "crunch" it, - * or accept it. Called from `sed'. + * Log cookie to the jar file. Then "crunch", + * accept or rewrite it to a session cookie. + * Called from `sed'. + * + * TODO: Allow the user to specify a new expiration + * time to cause the cookie to expire even before the + * browser is closed. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -2789,8 +3785,13 @@ jb_err server_http(struct client_state *csp, char **header) * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -jb_err server_set_cookie(struct client_state *csp, char **header) +static jb_err server_set_cookie(struct client_state *csp, char **header) { + time_t now; + time_t cookie_time; + struct tm tm_now; + time(&now); + #ifdef FEATURE_COOKIE_JAR if (csp->config->jar) { @@ -2801,17 +3802,15 @@ jb_err server_set_cookie(struct client_state *csp, char **header) * the %z field in strftime() */ char tempbuf[ BUFFER_SIZE ]; - time_t now; - struct tm tm_now; - time (&now); + #ifdef HAVE_LOCALTIME_R tm_now = *localtime_r(&now, &tm_now); #elif FEATURE_PTHREAD pthread_mutex_lock(&localtime_mutex); - tm_now = *localtime (&now); + tm_now = *localtime (&now); pthread_mutex_unlock(&localtime_mutex); #else - tm_now = *localtime (&now); + tm_now = *localtime (&now); #endif strftime(tempbuf, BUFFER_SIZE-6, "%b %d %H:%M:%S ", &tm_now); @@ -2822,8 +3821,8 @@ jb_err server_set_cookie(struct client_state *csp, char **header) if ((csp->action->flags & ACTION_NO_COOKIE_SET) != 0) { - log_error(LOG_LEVEL_HEADER, "Crunched incoming cookie -- yum!"); - return crumble(csp, header); + log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header); + freez(*header); } else if ((csp->action->flags & ACTION_NO_COOKIE_KEEP) != 0) { @@ -2864,22 +3863,93 @@ jb_err server_set_cookie(struct client_state *csp, char **header) next_tag = cur_tag + strlen(cur_tag); } - /* Is this the "Expires" tag? */ - if (strncmpic(cur_tag, "expires=", 8) == 0) + /* + * Check the expiration date to see + * if the cookie is still valid, if yes, + * rewrite it to a session cookie. + */ + if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8)) { - /* Delete the tag by copying the rest of the string over it. - * (Note that we cannot just use "strcpy(cur_tag, next_tag)", - * since the behaviour of strcpy is undefined for overlapping - * strings.) - */ - memmove(cur_tag, next_tag, strlen(next_tag) + 1); + char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */ - /* That changed the header, need to issue a log message */ - changed = 1; + /* Did we detect the date properly? */ + if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time)) + { + /* + * Nope, treat it as if it was still valid. + * + * XXX: Should we remove the whole cookie instead? + */ + log_error(LOG_LEVEL_ERROR, + "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url); + memmove(cur_tag, next_tag, strlen(next_tag) + 1); + changed = 1; + } + else + { + /* + * Yes. Check if the cookie is still valid. + * + * If the cookie is already expired it's probably + * a delete cookie and even if it isn't, the browser + * will discard it anyway. + */ + + /* + * XXX: timegm() isn't available on some AmigaOS + * versions and our replacement doesn't work. + * + * Our options are to either: + * + * - disable session-cookies-only completely if timegm + * is missing, + * + * - to simply remove all expired tags, like it has + * been done until Privoxy 3.0.6 and to live with + * the consequence that it can cause login/logout + * problems on servers that don't validate their + * input properly, or + * + * - to replace it with mktime in which + * case there is a slight chance of valid cookies + * passing as already expired. + * + * This is the way it's currently done and it's not + * as bad as it sounds. If the missing GMT offset is + * enough to change the result of the expiration check + * the cookie will be only valid for a few hours + * anyway, which in many cases will be shorter + * than a browser session. + */ + if (cookie_time - now < 0) + { + log_error(LOG_LEVEL_HEADER, + "Cookie \'%s\' is already expired and can pass unmodified.", *header); + /* Just in case some clown sets more then one expiration date */ + cur_tag = next_tag; + } + else + { + /* + * Still valid, delete expiration date by copying + * the rest of the string over it. + * + * (Note that we cannot just use "strcpy(cur_tag, next_tag)", + * since the behaviour of strcpy is undefined for overlapping + * strings.) + */ + memmove(cur_tag, next_tag, strlen(next_tag) + 1); + + /* That changed the header, need to issue a log message */ + changed = 1; + + /* + * Note that the next tag has now been moved to *cur_tag, + * so we do not need to update the cur_tag pointer. + */ + } + } - /* Note that the next tag has now been moved to *cur_tag, - * so we do not need to update the cur_tag pointer. - */ } else { @@ -2890,7 +3960,9 @@ jb_err server_set_cookie(struct client_state *csp, char **header) if (changed) { - log_error(LOG_LEVEL_HEADER, "Changed cookie to a temporary one."); + assert(NULL != *header); + log_error(LOG_LEVEL_HEADER, "Cookie rewritten to a temporary one: %s", + *header); } } @@ -2937,61 +4009,57 @@ int strclean(const char *string, const char *substring) } #endif /* def FEATURE_FORCE_LOAD */ + /********************************************************************* * * Function : parse_header_time * - * Description : Transforms time inside a HTTP header into - * the usual time format. + * Description : Parses time formats used in HTTP header strings + * to get the numerical respresentation. * * Parameters : - * 1 : header = header to parse - * 2 : tm = storage for the resulting time in seconds + * 1 : header_time = HTTP header time as string. + * 2 : result = storage for header_time in seconds * - * Returns : Time struct containing the header time, or - * NULL in case of a parsing problems. + * Returns : JB_ERR_OK if the time format was recognized, or + * JB_ERR_PARSE otherwise. * *********************************************************************/ -struct tm *parse_header_time(char *header, time_t *tm) { - - char * timestring; +static jb_err parse_header_time(const char *header_time, time_t *result) +{ struct tm gmt; - struct tm * timeptr; /* - * Initializing gmt to prevent time zone offsets. + * Zero out gmt to prevent time zone offsets. * * While this is only necessary on some platforms * (mingw32 for example), I don't know how to * detect these automatically and doing it everywhere * shouldn't hurt. */ - time(tm); -#ifdef HAVE_LOCALTIME_R - gmt = *localtime_r(tm, &gmt); -#elif FEATURE_PTHREAD - pthread_mutex_lock(&localtime_mutex); - gmt = *localtime(tm); - pthread_mutex_unlock(&localtime_mutex); -#else - gmt = *localtime(tm); -#endif - - /* Skipping header name */ - timestring = strstr(header, ": "); - if (strptime(timestring, ": %a, %d %b %Y %H:%M:%S", &gmt) == NULL) - { - timeptr = NULL; - } - else + memset(&gmt, 0, sizeof(gmt)); + + /* Tue, 02 Jun 2037 20:00:00 */ + if ((NULL == strptime(header_time, "%a, %d %b %Y %H:%M:%S", &gmt)) + /* Tue, 02-Jun-2037 20:00:00 */ + && (NULL == strptime(header_time, "%a, %d-%b-%Y %H:%M:%S", &gmt)) + /* Tue, 02-Jun-37 20:00:00 */ + && (NULL == strptime(header_time, "%a, %d-%b-%y %H:%M:%S", &gmt)) + /* Tuesday, 02-Jun-2037 20:00:00 */ + && (NULL == strptime(header_time, "%A, %d-%b-%Y %H:%M:%S", &gmt)) + /* Tuesday Jun 02 20:00:00 2037 */ + && (NULL == strptime(header_time, "%A %b %d %H:%M:%S %Y", &gmt))) { - *tm = timegm(&gmt); - timeptr = &gmt; + return JB_ERR_PARSE; } - return(timeptr); + + *result = timegm(&gmt); + + return JB_ERR_OK; } + /********************************************************************* * * Function : get_destination_from_headers @@ -3074,6 +4142,142 @@ jb_err get_destination_from_headers(const struct list *headers, struct http_requ } +/********************************************************************* + * + * Function : create_forged_referrer + * + * Description : Helper for client_referrer to forge a referer as + * 'http://[hostname:port/' to fool stupid + * checks for in-site links + * + * Parameters : + * 1 : header = Pointer to header pointer + * 2 : hostport = Host and optionally port as string + * + * Returns : JB_ERR_OK in case of success, or + * JB_ERR_MEMORY in case of memory problems. + * + *********************************************************************/ +static jb_err create_forged_referrer(char **header, const char *hostport) +{ + assert(NULL == *header); + + *header = strdup("Referer: http://"); + string_append(header, hostport); + string_append(header, "/"); + + if (NULL == *header) + { + return JB_ERR_MEMORY; + } + + log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header); + + return JB_ERR_OK; + +} + + +/********************************************************************* + * + * Function : create_fake_referrer + * + * Description : Helper for client_referrer to create a fake referrer + * based on a string supplied by the user. + * + * Parameters : + * 1 : header = Pointer to header pointer + * 2 : hosthost = Referrer to fake + * + * Returns : JB_ERR_OK in case of success, or + * JB_ERR_MEMORY in case of memory problems. + * + *********************************************************************/ +static jb_err create_fake_referrer(char **header, const char *fake_referrer) +{ + assert(NULL == *header); + + if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8))) + { + log_error(LOG_LEVEL_HEADER, + "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer); + } + *header = strdup("Referer: "); + string_append(header, fake_referrer); + + if (NULL == *header) + { + return JB_ERR_MEMORY; + } + + log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header); + + return JB_ERR_OK; + +} + + +/********************************************************************* + * + * Function : handle_conditional_hide_referrer_parameter + * + * Description : Helper for client_referrer to crunch or forge + * the referrer header if the host has changed. + * + * Parameters : + * 1 : header = Pointer to header pointer + * 2 : host = The target host (may include the port) + * 3 : parameter_conditional_block = Boolean to signal + * if we're in conditional-block mode. If not set, + * we're in conditional-forge mode. + * + * Returns : JB_ERR_OK in case of success, or + * JB_ERR_MEMORY in case of memory problems. + * + *********************************************************************/ +static jb_err handle_conditional_hide_referrer_parameter(char **header, + const char *host, const int parameter_conditional_block) +{ + char *referer = strdup(*header); + const size_t hostlenght = strlen(host); + + if (NULL == referer) + { + freez(*header); + return JB_ERR_MEMORY; + } + + /* referer begins with 'Referer: http[s]://' */ + if (hostlenght < (strlen(referer)-17)) + { + /* + * Shorten referer to make sure the referer is blocked + * if www.example.org/www.example.com-shall-see-the-referer/ + * links to www.example.com/ + */ + referer[hostlenght+17] = '\0'; + } + if (NULL == strstr(referer, host)) + { + /* Host has changed */ + if (parameter_conditional_block) + { + log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header); + freez(*header); + } + else + { + freez(*header); + freez(referer); + return create_forged_referrer(header, host); + } + } + freez(referer); + + return JB_ERR_OK; + +} + /* Local Variables: tab-width: 3